He was born the 21st day of June 1887, at Kenmore, Perthshire, Scotland, the second son of a landholder. He was named Murdo Bayne MacDonald, 'Bayne' being his mother's maiden name which he used as nom de plume.
His early childhood was spent in the strict religious environment of a typical Scottish family and when only six or seven years old he had a very moving spiritual experience. He saw the features of the Christ on the closed window of his room. Frightened by this, he fainted. After the experience he found he could see and hear things of which other people were unaware. He found too that he could jump from a height and stop himself in mid-air and slow down to land gently. This was a yoga feat of which he learned more when he grew up.
Yet it was also at that time when, going with his elder brother into the fields and jumping over a brook, he landed on a loose piece of barbed wire and one of the barbs penetrated his left eye. In hospital he was operated on by his uncle, who removed the eye and thereafter he always wore a glass eye.
As a young man he entered medical studies which he found too materialistically oriented, preferring to deal with the health-giving processes of life in a more natural way. Later on in life he was bestowed with the degrees of Doctorate of Divinity and Philosophy.
In 1913 he married,, and two sons eventually were born of this union.
In 1914 when war was declared he joined the Highland Light Infantry and, being a champion piper, he was made "Pipe Major," serving throughout with distinction and earning his first commission on the 16th of September 1917 as Second Lieutenant, to become Lieutenant on the 16th of March 1919. He was honoured with the British War Medal, the Victory Medal, and the Military Cross.
It was in France at the battle of Somme that Dr Mac was badly wounded and left for dead on the field for four days. This is his own description of what happened:
"During that period of time spent 'on the other side', I was instructed to return to my physical body, for my work was to tell the Truth to the world. When they came to remove the corpses for burial in a mass grave one of the ambulance men heard my groans and said, 'There's a live one here!' I was brought to the medical field station and immediately operated on. I heard distinctly the doctor mentioning that there was a possibility of losing the other eye and I decided in myself that was not going to happen. During the whole operation I was aware of what was taking place, although unable to speak, for one of the wounds was in the throat. So, out of the body, I assisted at the operation. After recovery and convalescence, I rejoined the Forces and went through the Near East campaign."
He was demobilized in 1920 with a Victory Medal then took his family to New Zealand and Australia, but as the children grew older Mrs MacDonald-Bayne returned to England for their education.